Pond Life Identification

Transcription

1 Sussex Wildlife Trust Aq1 Pond Life Identification Woods Mill, Henfield, West Sussex BN5 9SD Caddis fly larva Water scorpion Water beetle Whirligig beetle Freshwater shrimp Mayfly nymph Newt tadpole Water mite Leech Flatworm Bloodworm

2 Pond skater Water hog louse Water flea Ramshorn snail Wandering snail Damselfly nymph Dragonfly nymph Great diving beetle larva Water boatman

3 Sussex Wildlife Trust Aq2 Pond Life Dial Woods Mill, Henfield, West Sussex BN5 9SD front inside dial To make dial 1. Cut out all four sections 2. Stick front inside and back inside dials together, back to back 3. Laminate three pieces (1 dial and 2 covers) 4. Use a split pin to attach the front and back covers to dial. This will allow the dial to rotate

4 sussex wildlife trust back inside dial

5 sussex wildlife trust front cover

6 sussex wildlife trust back cover

7 Sussex Wildlife Trust Aq3 Pond Life Branching Key shell no shell snail legs no legs Woods Mill, Henfield, West Sussex BN5 9SD legs 6 legs 8 legs transparent body not transparent newt water mite mosquito or midge larva bloodworm black colour has 3 tail projections lives in a case or tube oval body gills on body no gills on body caddis fly larva swims on back swims on front mayfly nymph long flat tails stumpy tails greater water boatman long oar shaped back legs lesser water boatman water beetle damselfly nymph back legs not oar shaped dragonfly nymph

8 Sussex Wildlife Trust Aq4 Pond Life Key 1. Has it a shell? Yes Go to 2 No Go to 4 2. Is the shell coiled? Yes Go to 3 No Pea Mussel Woods Mill, Henfield, West Sussex BN5 9SD Is the coiled shell flat or pointed? Flat Ramshorn Snail Pointed Pond Snail 4. Has it legs? Yes Go to 11 No Go to 5 5. Is the body in different sections? Yes Go to 7 No Go to 6 6. Has it got fins? Yes Fish No Flatworm 7. Has it got antennae? Yes Go to 9 No Go to 8 8. Has it got suckers? Yes Leech No Freshwater Worm 9. Has it got 2 breathing tubes on its back? Yes Mosquito Pupa No Go to Is the body transparent? Yes Midge Larva No (Red) Bloodworm 11. How many legs has it got? 4 Go to 12 6 Go to 14 8 Go to 25 more than 8 Go to Has it got a tail? Yes Newt No Go to Look at its skin. Smooth Frog Warty Toad 14. Can you see antennae? Yes Go to 16 No Go to Which way up does the animal swim? On back Greater Water On front Boatman Lesser Water Boatman

9 16. Has it got tail projections? Yes Go to 17 No Go to How many tail projections has it got? 1 Go to 18 2 Beetle Larva 3 Go to Has it got a pair of pincers? Yes Water Scorpion No Alder Fly Larva 19. Does it have gills on its body? Yes Mayfly Nymph No Go to Does it live in a tube? Yes Caddisfly Nymph No Go to What shape are the antenae? Thread like Great Diving Beetle Club like Whirligig Beetle Thin and as long as Go to 23 the 1st pair of legs 22. Does it have long and flat or Long flat Damselfly Nymph short and stumpy tail projections? Short stumpy Dragonfly Nymph 23. Is the head very long and thin? Yes Water Measurer No Go to Look at pairs of legs 1&2 Yes Pond Skater 1 is nearest the head. No Water Cricket Are they widely seperated? 25. Has it got 1 body part or 2? 1 Water Mite 2 Water Spider 26. Is the body flattened from side to side Side to side Freshwater Shrimp or top to bottom? Top to bottom Water Slater

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12 Sussex Wildlife Trust Aq6 Adaptations of Pond Creatures Feeding A carnivore is a meat eating animal. An animal that hunts is a predator. Its catch is its prey. Predators need to catch their food and so need special adaptations to capture their prey. Woods Mill, Henfield, West Sussex BN5 9SD Great Diving Beetle This large beetle is over 3cm long. It has sharp mouth parts (mandibles) to grip its prey. Great Diving Beetle Larva After catching its prey it pumps digestive fluid down two large curved pincers which are hollow extensions of its jaw. The internal parts of the prey are dissolved and the 'food' sucked back by the larva, leaving an empty skin. Water Scorpion The two front legs of the Water Scorpion are folded in on themselves like penknives. It uses these long legs to grab its prey and put it into the sharp piercing mouth parts. Dragonfly and Damselfly nymph Dragonfly and Damselfly nymphs have a modified lower lip (the mask) which is greatly elongated and hinged in the middle. They have sensory appendages (palps) which are modified to form moveable claws which grab the prey.

13 Breathing in Water There are a number of ways in which pond animals obtain oxygen. sussex wildlife trust Animals with gills Many pond animals breathe dissolved oxygen in the water by using gills. This means they can breathe underwater and do not need to come up to the surface for air. Mayfly nymph A Mayfly nymph has gills on its abdomen. It constantly moves its gills to obtain a fresh supply of oxygenated water. Damselfly nymph The three flat tail projections of the Damselfly nymph are in fact its gills. Frog and Newt tadpoles The tadpoles of frogs at first 'breathe' with gills and then develop lungs later when they begin to leave the water. Newt tadpoles have lungs but begin life by breathing through gills which are external and look like orange/pink hands on each side of their head. Animals that breath air from the water surface If people swim under water they must come up to the surface to breathe, use a breathing tube, or take air down with them. The following pond animals do the same. Great Diving Beetle The Great Diving Beetle's method of breathing can be compared to a diver breathing from an oxygen tank. It surfaces regularly to collect a bubble of air from the surface under its hard wing coverings. The bubble is then absorbed through spiracles (breathing holes). When it has used up all the oxygen in its bubble it has to come up for a new one. You can see this as a bubble or as a thin silver line. Water Boatman This animal collects and traps air around the hairs on its abdomen. You can see the air glistening silver especially on the Greater Water Boatman which swims on its back. Water Scorpion The method of breathing used by the Water Scorpion is like a person using a snorkel. It pushes its tail, which is really a long thin breathing tube, up through the surface of the water to breath.

14 Movement Under the Water sussex wildlife trust Fish Fish use their various fins to help them to move quickly and precisely. Frog Tadpole The frog tadpole uses its tail in an S shaped movement. Great Diving Beetle The Great Diving beetle uses its two back legs as paddles. These are covered with rear facing hairs which provide resistance in one direction only like a pair of oars. Its streamlined body helps it to move smoothly. Water Boatman Water Boatmen have large hairy hind legs with which they appear to 'row' themselves. On Top of the Water The pond has a 'skin' on its surface produced by surface tension. Some pool animals use this skin to help them to move around. Pond Skater Pond Skaters have long legs to help spread the load. They also have water repellent hairs on the ends of their legs. Whirligig beetles Whirligig beetles dash around in circles and figures of eight on the water surface. Their eyes are divided into two parts - one on top of the head to see above the surface and the other on the lower side to enable the beetle to see under the water. Line drawings Natural England

15 Sussex Wildlife Trust Aq7 Pond Investigations Use keys to identify pond creatures Use keys to identify pond plants Woods Mill, Henfield, West Sussex BN5 9SD Compare different habitats within a pond Dip in open water and areas with pond weed. Observe the difference in number of species and number of individuals in each area. Does the quantity of each catch change throughout a pond dipping session? Collect a data base of information about the pond This data can be analysed to find variation throughout the year and over the years. Think about using a uniform sampling technique eg 10 dips You may want to vary or keep constant the: location of dip depth of dip time of dip (in the day) time of dip (in the year) - is there a seasonal variation? method used (sweep or dip) How healthy or polluted is the pond? Look for evidence of pollution eg rubbish / oil film on surface. Take photos using a digital camera to record the state of the pond. The variety and type of species found in the pond give an indication of how healthy / oxygen rich the pond is. Use the pollution sheets to work out a biological index for your pond. How does this change throughout the year? How does this change as your pond matures?

16 How do pond animals move? Observe a variety of animals, looking particularly at how they move. Do they skate across the surface / swim in the water / crawl / glide? What part of the body does the animal use to make it move? Do they use their legs / antennae / wriggle their body? sussex wildlife trust How do some animals swim on the surface of the pond? Place a piece of tissue on the surface of a bowl of water. Float a needle on it to demonstrate the skin of the water. What happens to the tissue? / the needle? / the skin of the water? Look at how the tips of a pond skater's legs make a dent in the water. Add a drop of washing up liquid. What happens? What happens if the surface of the pond is destroyed by pollutants? What do pond animals feed on? Watch an animal carefully to see what it feeds on. If you don't see it feeding, make some observations. If it is a carnivore, it might have large eyes to help find its prey, large jaws for holding and biting its prey, large antennae to help find its prey, claws on its legs for catching and holding its prey and it might move fast If it is a herbivore, it is likely to be slower and might have a transparent body so you may be able to see its green gut contents Extension 1: construct food chains and food webs to show feeding relationships within the pond. Extension 2: compare the abundance of herbivores, carnivores and omnivores in the pond. How do pond animals get oxygen? Observe a tank of animals and note which come to the surface regularly and which ones remain below the surface. Extension: time the interval that different creatures remain under the water between breaths. What is the effect of depletion of oxygen in a pond on pond life? Many small creatures absorb oxygen through their body surface. Some snails come to the surface to fill a lung. Most small pond creatures have a gill (extrusion of the body wall) - these usually absorb oxygen. However the gills on a Mayfly nymph don't absorb oxygen themselves, but create a current over the surface of the organism enabling more efficient absorption. Beetles often come up to the surface for oxygen which they take down as silver bubbles trapped between their back and wing. Mosquito larvae hang below the water surface and collect oxygen through a tube which penetrates the water surface.

17 sussex wildlife trust Investigate the role of plants in producing oxygen in a pond. As well as being a food source for pond herbivores, pond plants also produce oxygen (a by-product of photosynthesis). Place some pondweed in a beaker of pond water with a funnel and up-turned test tube over the top and leave in a sunny position. Bubbles of oxygen should appear on the surface of the leaves and oxygen collect in the test tube. Investigate the effect of the seasons on the animal and plant life in a pond? Compare the number of species found in the summer and winter. Compare the abundance of organisms collected in summer and winter. Compare the distribution of plants on the margins and surface of the pond. Compare the number of animals found just below the surface, amongst the weed and just above the bottom of the pond. Record the water temperature throughout the year. Most plants die back in winter, leaving less food for animals. This means a decrease in abundance of animals in winter. As the water temperature drops, animals which have survived move to deeper warmer parts of the pond. Many insects survive the winter in the egg phase - eggs have a tough covering and survive severe conditions then hatch in the spring when the weather is better. Many plants also over-winter as seeds. Perennial plants may have underground stems which store food for new growth in the spring. Some plants produce special buds, which sink to the bottom of the pond and spend the winter there. Management and maintenance of a pond Consider making one year group responsible for the management and maintenance in a pond. Discuss the importance of balance in a pond and how this information is needed for effective maintenance. Use a digital camera to record the amount of weed in pond, vegetation height around the pond and water level. What effect does this have on the pond? More pondweed and shade means more plant debris which uses up vital oxygen supplies in the process of decay. Check for signs of pollution What might happen to the pond if it was left and no maintenance carried out?

18 Sussex Wildlife Trust Aq8 Animals & Water Quality We can find out about the water quality of a pond or river by looking at the animals which live in it. Some animals need well oxygenated water, where as others are able to live in unclean and poorly oxygenated water. The Biological Monitoring Working Party invented a system where each animal is assigned a score. Those which need clean / oxygenated water have a high score, those which can live in poor quality water have a low score. By monitoring the type of animals found, and adding the scores together, you will get a BMWP score for your pond which indicates the water quality. Woods Mill, Henfield, West Sussex BN5 9SD What did you find? Tick here Score Worms Midge Larvae Water Hoglouse Water Snails Leeches Alderfly Larvae Water Beetles Water Boatman Flatworms Freshwater Limpets Freshwater Shrimp Damselfly Nymph Caseless Caddis Larvae Dragonfly Nymph Cased Caddis Larvae Stonefly Nymph Mayfly Nymph What does your score mean? 0-15 Poor Moderate Good Excellent

19 Sussex Wildlife Trust Aq9 Investigating feeding relationships within a pond Aim: To use pond dipping data to determine the feeding relationships within a pond Woods Mill, Henfield, West Sussex BN5 9SD Method: Divide class into 6 groups, each group within a pond Each group identifies and tallies the number of each species caught and enters their data in the grid Results: Use keys and reference materials to find the feeding relationships and enter into the grid Creature Damselfly nymph Dragonfly nymph Mayfly nymph Flatworm Bloodworm Leech Greater waterboatman Lesser waterboatman Water louse Great diving beetle larva Caddis fly larva Mosquito larva Newt Pond skater Ramshorn snail Wandering snail Water flea Number of creatures collected Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Total Mean Feeding Group Key: H = herbivore C = carnivore O = omnivore S = scavenger Work out the totals and means. Draw a graph to show the relative numbers of each feeding group. Conclusion: Which creatures had the highest total and mean? What do you notice about the ration of the feeding groups? Can you explain why? What does this tell you about the food chains within the pond?

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21 Sussex Wildlife Trust Aq11 What Do Pond Invertebrates Eat? Woods Mill, Henfield, West Sussex BN5 9SD Name Food Feeding Type Flat worm Small invertebrates Carnivore eg mites, waterfleas Freshwater worms Decayed plants, algae Herbivore (detritus) Leech Worms, snails, shrimps Carnivore (parasitic) Water fleas Algae, bacteria, detritus Herbivore (detritus) Water louse Detritus Herbivore (detritus) Freshwater shrimp Plants, detritus Herbivore Water mites Water fleas, shrimp, Carnivore insect larvae (some parasitic) Insects Mayfly nymph (young) Algae (older) Other insects Herbivore Carnivore Pond skater Dead insects Carnivore Greater waterboatman Insects, shrimps, snails Lesser waterboatman Algae, detritus Carnivore Herbivore

22 Saucer bug Insects shrimps, snails Carnivore sussex wildlife trust Caddisfly larva (young) Algae, plants, detritus (older) Other insects Herbivore Carnivore Water scorpion Insects shrimps, snails Carnivore Diving beetle Any insect, snail or Carnivore crustacean. Great diving beetle will eat newts Damselfly nymph Insects, crustaceans Carnivore Alderfly larva Insects, crustaceans Carnivore Fly larvae Algae, detritus Herbivore - gnats, midges (filter feeders) Ghost larvae Water fleas Carnivore Molluscs Mussels Algae, detritus Herbivore (filter feeders) Winkles & valve snails Detritus Herbivore (detritus feeder) Pond snails Algae, plants Herbivore (grazing animal) Ramshorn snail Detritus Herbivore (detritus feeder) Notes Detritus is the name given to the dead, rotting remains of plants and animals at the bottom of ponds. Herbivores that feed on detritus are given the special name detritivores.